Dehardwarization
From Wikipedia, the free encyclopedia
Dehardwarization is an unofficial term defining a tendency in design of new computer hardware (in particular for IBM PC clones) which tends to eliminate as many hardware components as possible and supplanting their functionality with software, to various extents, effectively making such "hardware" heavily host-CPU and operating system dependent.
A prime example of dehardwarized devices include softmodems and many AC'97 based audio cards.
The former are stripped-down modems which lack their own Digital Signal Processor (and sometime even analog demodulators) which do all of the necessary signal processing (excluding voltage adaptation and A-D/D-A conversion) on the host computer's CPU, and are bound to be used in machines with a certain critical amount of processing power, memory and specific operating system, thus making the boundary between software and hardware very vague.
The AC'97 codec on the other hand is essentially a simple combined DAC and ADC which, on its own, can only play back from two to 5 or 7 distinct channels of digital audio and recording from two channels, while it lacks any hardware support for real-time DSP effects and even multi-voice playback, let alone MIDI music synthesis. The latter tasks, in fact are entirely dependent on software (its device drivers) and the host's CPU power.
A less dramatic example is represented by PC Tuner cards and video grabbers. In the mid-1990s , they used to be expensive devices with their own custom processors and memory, and diplayed their output via analog SVGA overlay or the internal feature connector found on some graphic cards, in order to avoid using the main system's bus as much as possible.
Conversely, modern designs use the system's bus and CPU with no problems, eliminating the need for more dedicated hardware, something only made possible by the advance in CPU power, system architecture and operating system reliability, to the point that even USB Tuner cards have appeared, with no analog passage or digital "bypass" at all, relying 100% on the system's raw power.
Similarly, it's common for modern low-end video capture card to completely lack any sort of dedicated DSP e.g. a MPEG compression module, relying on software and raw CPU power to perform the necessary calculations, and the capture card itself is essentially reduced to a high-speed video ADC.
Such design choices are popular for low-end or entry level products, and were made possible by the ever increasing computing power of modern CPUs and by the creation of new industry standards supporting them, but apparently lead to the paradox that e.g. a "modern" AC'97 based soundcard (usually built-in in a motherboard) is actually less sophisticated than an older Soundblaster or Gravis Ultrasound which have their own MIDI FM or Wavetable synthesizer.
